1. Field
The present disclosure relates to an optical module, a manufacturing method thereof and an electronic apparatus.
2. Description of the Related Art
An optical module, for example, a proximity sensor, can be used to sense an object near the optical module. The optical module may include a light-emitting component and an optical sensor, where the optical sensor can sense light emitted by the light-emitting component and reflected by an object. By way of example, when the optical module is included within a smartphone, the optical sensor may sense light reflected from a facial surface of a user of the smartphone.
Optical cross talk can cause diminished sensitivity of the optical sensor to desired reflections. In the smartphone example, optical cross talk can cause diminished sensitivity of a proximity sensor to reflections from the facial surface of the user of the smartphone. Optical cross talk may be light emitted by the light-emitting component and reaching the optical sensor directly; cross talk may also be light emitted by the light-emitting component but reaching the optical sensor via reflection from another medium other than the object to be sensed. In the smartphone example, cross talk can include light reflected from objects other than the facial surface of the user, such as reflected from a display screen glass of the smartphone.
A lid including an opaque material may be used to block optical cross talk occurring due to light emitted by the light-emitting component directly reaching a photosensitive region of the optical sensor. However, the photosensitive region may also receive optical cross talk in the form of unwanted reflected light, which may not be blocked by the lid. For the smartphone example, the photosensitive region may receive light reflected from one or both surfaces of the display screen glass, which may account for as much as about 80% of received power.
A distance between the light-emitting component and the optical sensor can be increased, to reduce optical cross talk from unwanted reflected light. However, increasing the distance between the light-emitting component and the optical sensor will increase a size of the optical module, which generally goes against a prevailing trend of decreasing the size of many electronics while adding functionality, such as is the situation for smartphones and other devices.